I. Field of the Invention
The present invention relates to building construction and, more particularly, to support structures for large span, multiple deck space frame systems and for multiple module frames which are accordingly capable of providing high load carrying capacity.
II. Description of the Priot Art
The C. W. Attwood U.S. Pat. No. 3,270,478, C. W. Attwood et al. U.S. Pat. No. 3,421,280 and the H. V. Papayoti U.S. Pat. No. 3,443,348, all of common ownership herewith, disclose a standardized system for space frame construction involving the use of lightweight, freely interchangeable elements of high quality material, manufactured to close tolerances that can be assembled at relatively low cost even by comparatively inexperienced workers to form structures varying greatly in design and capable of being readily disassembled, altered or expanded to meet the changing needs of the user, the components being almost 100% salvageable. Such a flexible type of structural framework is well suited for many different types of buildings, pavilions, three dimensional trusses, docks, structural spans and the like. In addition, such a structural framework meets not only the requirements of flexibility, standardization and quality, but is capable of carrying large loads and can be engineered to form space enclosures of various sizes and shapes instead of being limited within certain overall fixed dimensions as is the case with conventional structures.
As disclosed in the aforesaid patents, a space frame is a structure in which forces act in three or more directions in space. The structure uses four substantially standardized basic parts; namely, connecting fixtures, struts, bolts and nuts. The connecting fixture is a preformed universal element having horizontally and angularly located seats with accurate locating and securing means included to which the struts are attached by the nuts and bolts. The space frame systems can be applied in assemblies of roof span constructions as well as floors, ceilings, sidewalls and other like structures.
Until the appearance on the market of the space frames known by the trademarks "UNISTRUT" and "ATTWOOD SYSTEM," trusses and the like used in floors, roofs and other building parts were either welded together and carried to the construction site or were assembled by welding, riveting or bolting in the field. Specified and predrawn parts, which individually were adapted for only one specialized use, had to be altered in size and form as the construction progressed. The shortcomings and the inconveniences of prior construction systems were overcome by the space frame system of construction utilizing lightweight, easily handled modular parts. Since these parts are manufactured in large quantities and are accurately dimensioned, the interchangeability of the parts is a prime advantage. The precision and accuracy with which the parts are made in the factory insure speed and proper results in assembly. The parts arrive on the site prefinished and are readily joined together. Workmen do not have to use tapes or squares in assembly and the simplicity of assembly even permits employment of relatively unskilled labor. Such space frame structures provide a building construction having a roof structure and a floor structure that are held in a rigid column support system to provide ready and reliable basic construction.
One problem which arose was that of providing a support structure which in combination with the support column would lend sufficient support to a multiple deck space frame capable of supporting greatly increased loads and generally extending laterally over not one but two or more modules. Support columns and column arm arrangements known to the prior art proved inadequate to afford support to the relatively wide span multiple deck space frames and there was the need of structural capacity and reasonably minimum deflection of the support column arm members.
It thus became a problem to provide a support structure which would support greatly increased loads and transmit the stresses involved in a space frame arrangement without disrupting its basic geometry, the structural unity and simplicity of its parts.